ok...for a race 350 whats the advantage of an aftermarket block such as a dart or "motown" block over a new GM 4 bolt main production 350 block? I mean you could literally crack 3 production blocks in half before you exceed the cost of an aftermarket...... keep in mind this is for advantages for a 350 not some crazy 454 small block strocker.

just wondering

 

Aftermarket race blocks are typically beefier and have siamesed cylinders for monster bores, sorta like a GM 400 sb. Some have taller or shorter deck heights too.

 

because a production 350 block is only a 350.

you can take a motown out to a 454 my having a shop bore it and buying a stroker kit...

a dart block can come in alum, and that means alot less weight..

mostly though, in the smaller bores, they are ALOT beefier and can take insane cyl pressures.

in that case....... it is a waste of money. thats why most people have 350s

 

The Dart blocks have the thick cylinder walls as stated , scalloped water jackets that flow around the cylinders to cool it better. Nice thick decks, priority main oiling system oils the mains first. Blined tapped head bolt holes and splayed four bolt mains. You said that you could go through 3 production blocks before you got to the cost of an aftermarket block, but often when a block takes a puke it gets more than just the block. So if you break a main cap, more than likely your gonna get the crank and other things as well.